So, I bought one to try on my CS MK2 w/ CyberScsi module on my A4000. No Joy. I took the CF card that I am booting the A4000 from (on a Fast ATA MK VII), and put it in the SCSI-CF adapter. Set the terminator on and the SCSI ID via its jumpers. Tried all three possible IDs that it offers, turned termination on and off, set term power on and off, and, nothing but the Kickstart screen appears, asking for a disk. The card's LEDs illuminate, indicating it's getting power, and the read/write LED on the card will flicker for a second or two, indicating the SCSI module is trying to access it, but, it won't boot. I've tried 4,16,32 GB Sandisk CFs and a 4GB Kingston, all of which are system drives on other Amigas I own, but, nothing boots.
If I should boot the A4000 from the Fast ATA, while having a CF card on the SCSI-CF adapter card, I can open up HDToolbox in 3.9. I can indeed select it, it shows up as SCSI-IDE-Bridge, or something similar, but, when I click on it to view the partition tables on the CF card, I get an error stating that HDToolbox cannot be used on this type of drive (or something similar to what one gets if you try to select a SCSI CDROM drive with HDtoolbox).